Routing configuration validation apparatus and methods

#This invention relates generally to electronic communications and, in particular, to validating routing configurations used in a communication network.

#The global Internet Protocol (IP) address space currently offers a theoretical maximum of 4,294,967,296 hosts (232). In reality, this address space has been allocated in fairly large contiguous blocks. Address allocation authorities distribute blocks of the IP address space to individual organizations interconnected through networks that make up the Internet as a whole.

#These address blocks must be globally reachable according to routing information exchanged via routing protocols such as Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Intermediate System to Intermediate System (IS-IS). Routing information, which is both used locally and exchanged with peers, generally refers to address blocks in terms of an IP address and a mask, called a Classless Inter-Domain Routing (CIDR) block. For example, an IP address block written 192.172.226/24 refers to all IP addresses having the same prefix for the first 24 bits (i.e. 192.172.226). This block starts at address 192.172.226.0 and contains 256 possible individual IP addresses (232-24). Routing tables associate this IP address block, which includes an address/mask pair, with a next hop IP address, and routers forward all traffic with a destination IP address in this block to the next hop listed in their local routing tables.

#Examples of embodiments of the invention will now be described in greater detail with reference to the accompanying drawings, in which:

#FIG. 1 is a block diagram of a communication system incorporating an embodiment of the invention;

#FIG. 2 is a block diagram of a routing configuration validation system;

#FIG. 1 is a block diagram of a communication system 10 incorporating an embodiment. The communication system 10 includes communication networks 12, 14, 16, which are interconnected through respective routers 13, 15, 17. A routing configuration validation system 18 is operatively coupled to one or more of the routers, the router 17 in the example shown in FIG. 1.

#The particular system topology and components shown in FIG. 1 are intended solely for illustrative purposes, and not to limit the scope of the invention. For example, a communication system may include fewer or more than three communication networks 12, 14, 16 and/or different inter-network connections than explicitly shown in FIG. 1. Communication networks also generally include additional routers and other equipment, which have not been shown in FIG. 1 to avoid congestion. It should therefore be appreciated that the system of FIG. 1, as well as the contents of the other drawings, are intended solely for illustrative purposes, and that the present invention is in no way limited to the particular example embodiments explicitly shown in the drawings and described herein.

#The communication networks 12, 14, 16 represent interconnected communication equipment through which communication traffic is transferred. End user equipment (not shown) which is operatively coupled to the communication network 12, for example, can exchange communication traffic with other equipment in the network 12, and, through the border routers 13, 15, 17, with equipment in the other networks 14, 16.